Traveling crane



Aug. 31, 192d 1,598,273

' B. F. FITCH TRAVELING CRANE Filed Jan- 5, 1925 3 Sheets-sheaf anvcmtozaw, fl @141 B. F. F ETCH TRAVELING CRANE Filed Jan. 5, 1925 3Sheets-Sheet 2 muom roa gkm M /M (than my Aug. 31, 1926. 1,598,273

B. F. FITCH TRAVELING CRANE:

Filed Jan. 5 1925 3 Sheets-Shet 5 x i 4 33 v Rel y Z1 (,L m

Patented Aug. 31, 1926.

BENJAMIN F. FITCH, OF GREENWICI-I, CONNECTICUT.

TRAVELING CRANE.

Application filed. January 5, 1925.

This invention relates to a mechanism for skewing or lifting a loadwhich is suspended from a crane, and is concerned primarily withimprovements in U. S. Patent No. 1,437,967 issued to me December 5,1922.

Briefly, the mechanism illustrated in my patent embodies a frame whichis arranged to travel on an overhead trackway with hoisting mechanismincluding drums and cables carried thereby. The cables are illustratedas passing over sheaves which are disposed adjacent the corners of atheoretic rectangle. Two of the sheaves are shiftable axially,wherefore, one end of a load suspended from the cables may be skewedwith reference to the crane in order to position the load moreaccurately with reference to a truck. One of the objections to the useof mechanism which moves the sheaves in a straight line is the fact thatone end of the load is raised slightly due to the shifting operation.Accordingly, if hand poweris employed for the skewing operation, thenconsiderable force must be exerted to effect the shifting operation.

The principal object of the present invention therefore, is theprovision of mechanism which enables the load to be skewed withoutrequiring it to be moved vertically during the twisting operation. Anadvantage of this construction is that the mechanism employed forshifting the load need only be sufliciently strong to overcome frietiondue to lateral movement of the sheaves with reference to the supportingframe.

I carry out the above object by employing sheaves which are shiftablelaterally with reference to the frame being preferably mounted in rollercarriages, and by utilizing curved trackways for supporting two of thesheaves. In addition, I arrange mechanism for moving such sheavessimultaneously whereby one end of a suspended load is shifted withreference to the frame. By making the trackways upon the arc of acircle, then each shiftable sheave can be moved without raising'one endof the load. ,The arcuate path in which each sheave moves is determinedby the relative position of the movable sheave to other sheaves whichare employed for guiding the cables along the frame.

Preferred means for carrying out my in vention is fully set forth in thefollowing description which relates to the accompanying drawings,wherein Fig. 1 is a plan view Serial No. 535.

of a crane embodying my invention; Figs. 2, 3, 4 and 5 are sectionstaken on the correspondingly numbered lines in Fig. 1, and Fig. 6 is asection taken on the line 66 in Fig. 5; Fig. 7 is a detail Viewillustarting a safety device for the screw and nut couple; Fig. 8 is asection taken transversely through the couple shown in Fig. 7.

My invention is shown in connection with an overhead hoisting mechanismwhich is employed for engaging, raising and transporting removableautomobile bodies. Accordingly in the various figures, 10 indicates aset of overhead tracks which support the traveling crane wheels 11 andconstitute a trackway therefor. The wheels are journaled within a framewhich may comprise longitudinal members 12, and transverse members 13which I arrange in the form of a rectangle. The frame work may comprisechannel beams which are held together in any convenient manner.

The hoisting mechanism shown comprises cables 14, 15, 16 and 17, whichextend over sheaves 18, 19, 20 and 21 respectively. The sheaves arearranged adjacent the corners of a rectangle, whereby the verticalreaches of the cables may engage a removable truck body adjacent thefour corners of a rectangle. To move the sheaves simultaneously, I haveshown a screw and nut couple which is disposed adjacent the mid-portionof the frame. The nut as shown is attached to the cables and is arrangedto be guided while moving longitudinally of the frame by guides 22 and23. Such movement is effected whenever the screw or threaded shaft 24 isrotated.

In the preferred form the nut embodies two members 7 and 8 which may beloosely connected by dowel pins 9. The nut 7 is ordinarily of bronze andis arranged to carry the load stresses, while the nut 8 is preferably ofsteel and is normally idle but may carry the load as an emergency in theevent of failure of the nut 7 due to wear on the threads. The nuts arenormally out of contact, but clearance beyond the dowel pins in theirsockets allows the bronze nut, should its thread be stripped, to comeagainst the steel nut, which will thus support the load. This feature iscovered in my divisional application No. 42,891 filed July 11, 1925.

To guide the cables, I have shown sheaves 26 and 27 which are disposednear one end of the frame for guiding the cable 14. Similar sheaves 28and 29 are utilized for guiding the cable 15. Sheaves 30 and 31preferably mounted on the same axis as the sheaves 26 and 27 are usedfor directing the cable 16, while sheaves 32 and 33 mounted on the sameaxis as the sheaves 28 and 29 are employed for guiding the cable 17.

To rotate the shaft 24, I have indict ted a hand chain wheel 3% which ismounted upon a shaft 35 and is operatively connected by gearing 36 tothe shaft 24;. A thrust bear- -ing 37 may be disposed at one end of theshaft, whereby load stresses place the shaft under tension and therebyprevent deflection of the shaft while in use.

The sheaveslS and 19 are shiftable laterally upon curved trackways withreference to the frame for twisting the load with reference to theframe. The trackway for the sheave 18 is indicated as embodying an l.-shaped member 40 which extends between one of the beams 12 and areinforcing beam A similar curved trackway for the sheave 19 isindicated at 11 as extending between one of the beams 12 and areinforcing beam 6. In the preferred form, the sheaves 18 and 19 arerotatably mounted within carriages 4C2 1111(l4r3 respectively, and thecarriages are operatively connected for simultaneous movement. Asillustrated, each carriage has horizontally disposed wheels 44 whichengage one arm of the curved trackway, and have vertically disposedwheels 41-5 for engaging the other arm of the traclnvay. Retainingmembers 46 and 47 may be positioned on the trackway for guiding the carriages during movement thereof.

The curvature of the trackways 4:0 and 11 permit the lateral shifting ofthe carriages with reference to the frame without raising the load. Toeffect such operation the curvature of the track is determined by theare of a circle which is described about a center which is the point oftangency of the horizontal sheave from which the cable runs to theshiftable vertical sheave. Thus the track 40 is an are about the pointA, while the curvature of the track 41 is defined by the arc of a circlewhichis described about the point B as a center. 'he points A and B aredetermined by the intersection of a line passing transversely of theframe thru the axes of the sheaves 26 and 29.

To shift the carriages simultaneously, I have shown a connecting rod 50which is pivotally connected at 51 to the carriage 43 and at 52 to thecarriage 4:2. Therod is illustrated as having a rack 53 which may beengaged by a pinion 54. To rotate the punch and therefore to shift therack, I have indicated a hand chain wheel 55. which is mounted'upon ashaft 56. This shaft also carries the pinion. Accordingly, if the chainwheel is rotated 1n one direction, the carriages are simultaneouslyshifted in one direction, while if the chain wheel is rotated in theopposite direction, the directional movement of the carriages isreversed.

From the foregoing description, it w li be evident that I have providedasimple means for twisting a load with reference to the supporting framewithout redu 4 one end of the load to be raised during the shiflingoperation. Moreover, I have obtained a mcchanisnr which is adapted foruse with a hoisting apparatus which includes a screw and nut couple,wherefore the skewing device maybe mounted wit iin a crane having a verylow over-all depth. This facilitates the installation within a buildingof low height without necessitating extensive changes in the buildingconstruction.

Having thus described my invention, I claim:

1. In combination, a frame, a sheave carried thereby, a lifting cableextending substantially the entire length of the frame and having ahorizontal reach which at one end passes over the sheave and thendepends, and means for shifting said sheave in an arcuate path aboutcenter substantially coincident with the other end of said horizontalreach, whereby a load nniy be twisted with reference to the frame.

2. In combination, a frame, load engaging elements depending therefrom,means for raising or lowerin said elements, and means if for shiftingsome of said elements in a curved path and with reference to theremaining elements for skewing a load with reference to the frame.

3. In combination, a frame, sheaves rot-atably mounted thereon, flexibleload engaging elements extending over the sheaves, means for raising orlowerin said elements, and means for shifting some of said sheaves in acurved path with reference to the remaining elements for skewing a loadwith reference to the frame.

4. In combination, a frame, sheaves carried thereby, cables passing overthe sheaves, and means for shifting some of said sheaves in an arcuatepath with reference to the remaining sheaves, whereby a load dependingfrom said cables may be twisted with reference to the frame.

5. In combination, a frame, sheaves carried thereby and arranged inpairs, cables passing over the sheaves, two of said sheaves beingshiftable in a curved path with reference to the remaining sheaves, thepath of travel of the two sheaves being similar, whereby a loaddepending from the cables may be skewed with reference to the frame.

6. In combination, a frame, a plurality of sheaves carried thereby, andcables extending in horizontal reaches for substantially the entirelength of the frame and then passing over the sheaves, two of saidsheaves being shiftable along arcuate paths with reference to theremaining sheaves, the ra 7. In combination, a ,frame four sheavesmounted thereon, caoles passing over the sheaves, curved trackways fortwo of said sheaves, means for raising or lowering said cablessimultaneously, and means for moving two of said sheaves along thecurved trackway simultaneously, said traclrways having such curvaturethat a load suspended from the cables may be twisted while the loadremains level.

8. In combination, a rigid frame, four sheaves mounted thereon, fourflexible raising members depending from said sheaves, and means formoving two of said sheaves in a curved path with relation to said frameand with relation to the remaining sheaves.

9. In a hoisting mechanism, the combina tion with a rigid frame, of fourflexible rais ing elements mounted thereon, means for simultaneouslyraising or lowering said elements. four sheaves over which said elementsextend, and means for shifting two of said sheaves as a unit alongsimilarly curved paths relatively to the frame, and relatively to theother two sheaves.

10. In combination, a frame, two similarly curved trackways carriedthereby, said trackways having spaced centers of curvature, a carriageon each trackway provided with a bearing wheel and having a sheave,cables extending horizontally to the respective sheaves and thendepending from each carriage, a member operatively connecting thecarriages and means for shifting the member transversely of the frameand of the horizontal reaches of the cables to move the carriagessimultaneously in the same direction along the respective trackways.

1].. In combination, a frame, two arcuate traclrways carried thereby,said trackways having equal radii of curvature and different centers ofcurvature two wheeled-carriages movable along said trackways,respectively, a sheave mounted in each carriage, a flexible raisingmember passing over each sheave and having a load engaging member at itsfree end, means for moving the carriages simultaneously in the samedirection with reference to the frame and along the respectivetrackways, whereby a load suspended from the cables may be shiftedlaterally.

12. In combination, a frame, two curved trackways carried thereby andhaving differentcenters of curvature, a wheeled carriage movable alongeach trackway, a sheave mounted in each carriage, a flexible raisingmember passing over each sheave, means for moving the carriagessimultaneously with reference to the frame and along the respectivetraclnvays, whereby a load suspended from the cables may be shiftedlaterally while being maintained at the same height.

13. In combination a frame, two wheeledcarriages thereon. some of thewheels on the carriage being disposed on a vertical axis and others on ahorizontal axis, sheaves mounted in the respective carriages, cablesextending horizontally and then depending over the sheaves, a memberconnecting the carriages, a trackway on the frame engaging both thevertical and horizontal wheels, and means for shifting the membertransversely of the horizontal reaches of the cable to move thecarriages simultaneously along said trackway.

14L. The combination of a frame having transverse members withhorizontal and vertical surfaces, a pair of carriages bearing againstsaid horizontal and vertical sun faces, a pair of sheaves mounted in there spective carriages, lifting cables extending horizontally over thesheaves and then depending, and means for shifting said carriages.

15. In a hoisting mechanism. the combination of a traveling frame. atransverse trackway thereon having substantially horizontal andsubstantially vertical portions, a pair of carriages having rollersbearing against said portions, a pair of sheaves mounted in saidcaniages respectively, cables extending horizontally over the sheavesand then depending to a load, means connecting the two carriages, andmechanism engaging said connecting member to shift the carriages ineither direction, the vertical portion of said trackway being madeareuate.

In .estimony whereof, I hereunto afiix my signature.

BENJAMIN F. FITCH.

